In
mass transfer
Mass transfer is the net movement of mass from one location (usually meaning stream, phase, fraction or component) to another. Mass transfer occurs in many processes, such as absorption, evaporation, drying, precipitation, membrane filtration ...
, the sieving
coefficient is a measure of
equilibration between the
concentration
In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: '' mass concentration'', ''molar concentration'', '' number concentration'', ...
s of two mass transfer streams. It is defined as the
mean
There are several kinds of mean in mathematics, especially in statistics. Each mean serves to summarize a given group of data, often to better understand the overall value (magnitude and sign) of a given data set.
For a data set, the '' ari ...
pre- and post-contact concentration of the mass receiving stream divided by the pre- and post-contact concentration of the mass donating stream.
where
* ''S'' is the sieving coefficient
* ''C''
r is the mean concentration mass receiving stream
* ''C''
d is the mean concentration mass donating stream
A sieving coefficient of
unity
Unity may refer to:
Buildings
* Unity Building, Oregon, Illinois, US; a historic building
* Unity Building (Chicago), Illinois, US; a skyscraper
* Unity Buildings, Liverpool, UK; two buildings in England
* Unity Chapel, Wyoming, Wisconsin, US; ...
implies that the concentrations of the receiving and donating stream equilibrate, i.e. the out-
flow concentrations (post-mass transfer) of the mass donating and receiving stream are equal to one another. Systems with sieving coefficient that are greater than one require an external
energy
In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of hea ...
source, as they would otherwise violate the
laws of thermodynamics
The laws of thermodynamics are a set of scientific laws which define a group of physical quantities, such as temperature, energy, and entropy, that characterize thermodynamic systems in thermodynamic equilibrium. The laws also use various paramet ...
.
Sieving coefficients less than one represent a mass transfer process where the concentrations have not equilibrated.
Contact time between mass streams is important in consider in mass transfer and affects the sieving coefficient.
In kidney
In
renal physiology
Renal physiology (Latin ''rēnēs'', "kidneys") is the study of the physiology of the kidney. This encompasses all functions of the kidney, including maintenance of acid-base balance; regulation of fluid balance; regulation of sodium, potassium, ...
, the glomerular sieving coefficient (GSC) can be expressed as:
sieving coefficient =
clearance /
ultrafiltration rateSieving coefficient in drug clearance
- cuhk.edu.hk
See also
*Heat exchanger
A heat exchanger is a system used to transfer heat between a source and a working fluid. Heat exchangers are used in both cooling and heating processes. The fluids may be separated by a solid wall to prevent mixing or they may be in direct conta ...
* Condenser pinch point
*Sieve
A sieve, fine mesh strainer, or sift, is a device for separating wanted elements from unwanted material or for controlling the particle size distribution of a sample, using a screen such as a woven mesh or net or perforated sheet materia ...
References
Transport phenomena
Chemical engineering
Mechanical engineering